The Heian Maru is the largest wreck still in Truk Lagoon. She was built in 1930 as a passenger / cargo liner, but was converted in to a submarine tender. She was sunk on the 2nd day of Operation Hailstone when a torpedo hit her engine room. She now lies on her port side in about 35 metres of water, but because of her size, her starboard side is at 12 metres.
This is a great wreck, and one dive barely scratches the surface of what there is to see. We focused on the central section and the bow, but still only saw a fraction of it. The merchant ships generally follow a similar pattern, with 2 or 3 holds either side of a central superstructure containing the engine room. But the liners have the addition of, in this case, three decks on a much larger superstructure, which makes them more complex from a diving point of view. This, combined with the size of the Heian Maru, made this a wreck we wanted to come back to.
There is a companionway running along the superstructure containing some very long tubes which were periscopes /snorkels for submarines, as you can see in Catheryn’s photo:
Passageway on Heian Maru (Photo: Catheryn Chu)
Since she lies on her side, once you get a bit deeper into the superstructure it can be very dark. We went into the engine room, where there was a skull, a reminder of the loss of life that happened here. From there, we explored more of the superstructure and the upper companionways, before heading round to the forward holds. Finally we came up to the bow, where you can still clearly see the ship’s name in both English and Japanese.
As we headed along the side back to the line, there were a variety of artefacts that have been placed there, as you can see in Catheryn’s photos below:
Wing, phoning home (Photo: Catheryn Chu)
More artefacts on Heian Maru (Photo: Catheryn Chu)
Heian Maru
- Displacement: 11,616 tons
- Length: 510 feet
- Beam: 66 feet
- Engine: 2 diesels
- Depth: 12 – 35 m.
Our Dive
- Depth: 27.8 m.
- Time: 57 minutes
- Gas: Nitrox 32
Graphic courtesy of Captain Lance Higgs of S.S. Thorfinn.
